A wireless communication system may include a first station able to communicate with a second station over a communication channel. In a spatial multiplexing communication system the first station may include a transmitter to transmit parallel streams representing a message via a plurality of transmit antennas (NTX>1). The second station may include a receiver to receive a plurality of symbols corresponding to the transmitted streams via a plurality of receive antennas (NRX≧NTX).
The receiver may include an equalizer to decode the received symbols, which may be a mixture of the transmitted symbols, into metrics (LLRs). The receiver may also include a Maximum Likelihood Sequence Estimation (MLSE) decoder, e.g., a turbo decoder or a viterbi decoder, to determine an estimation of the message based on the metrics.
The equalizer may determine the metrics based on a Maximum Likelihood Decoding (MLD) algorithm, which may include scanning all constellation points of all the NTx, transmit antennas. Accordingly, the MLD algorithm may have a complexity of MNTx, wherein M denotes a constellation size implemented by the transmitter. For example, if NTX=2, and M=64, then the MLD algorithm may have a complexity of 4096.
It will be appreciated that for simplicity and clarity of illustration, elements shown in the drawings have not necessarily been drawn accurately or to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity or several physical components included in one functional block or element. Further, where considered appropriate, reference numerals may be repeated among the drawings to indicate corresponding or analogous elements. Moreover, some of the blocks depicted in the drawings may be combined into a single function.